Outdoor explorers may fail to take altitude into account when visiting high-altitude recreation areas, which puts them at risk of developing fatigue and other symptoms related to being high above sea level, according to Dr. Melissa Tabor, an assistant professor of sports medicine and osteopathic principles and practice at Nova Southeastern University College of Osteopathic Medicine in Fort Lauderdale, Fla.

"No matter how great of an athlete you are, if you are coming from sea level or lower altitudes to a higher altitude area, you need to prepare," Tabor said in a news release provided by the American Osteopathic Association. Tabor recently gave a presentation on preparing for high-altitude activities at the Osteopathic Medical Conference in Seattle.

People under 50 more likely to get altitude sickness, Tabor said.

Folks should be on the lookout for signs of altitude sickness: nausea, vomiting, dizziness, fatigue, sleep disturbances and poor eating. Other more serious symptoms include confusion, inability to walk, shortness of breath and coughing blood. In extreme cases, altitude sickness can even cause death, according to Tabor.

Fortunately, treatment is often simple -- move to a lower altitude, she noted.

Acclimate to higher altitude by spending days -- or weeks, if possible -- at a higher altitude before any strenuous activity.

Plan ahead and get information about the location where you're traveling. You may be able to find websites created by mountain resorts and local governments with details about ascending and descending.

Climb slowly and check guidelines from the Wilderness Medical Society.

Listen to your body and don't climb any more if you feel lightheaded or have a headache. Descend within two to four hours if the symptoms don't go away.

Stay hydrated and drink before you're thirsty.

Consider renting a portable hyperbaric chamber to help you adjust to altitude.

Talk to a doctor for advice and possible prescriptions for medications that may help you adjust to altitude.